>Fingerprints of Global Warming
>Terry Root is a biologist and Senior Fellow at the Center for
>Environmental Science and Policy (CESP) at Stanford's Institute
>for International Studies. CESP, formalized in 1998, brings
>together science and policy analysis to evaluate the forces that
>drive environmental and resource problems and the social and
>political responses to these problems.
>Dr. Root will describe her research on the changes in the behavior
>of birds in response to temperature increases, and forecasting the
>possible consequences of global warming on animal communities.
Dr. Root began her presentation by making a couple of comments about people who don't believe in Climate Change caused by human behavior. She punctuated them by showing us a cartoon of an extinct SUV in a museum where a docent was explaining it probably went extinct because of its huge size. Everybody laughed at that one. Then she explained that the predicted warming was enough that you could expect bird populations, which are highly mobile, to respond in measurable ways. That had been the inspiration for her studies.
Bird behavior changes have been part of the Climate Change dialog for a while. During the early 1990s a student of hers had studied the effect of climate change on the Bay-Brested Warbler, Tennessee Warbler and Blackburnian Breasted Warblers, his prediction was that their ranges would almost vanish by 2020 because of Climate Change's dramatic effect on their habitat. Al Gore used to carry around a slide that showed the range of the Baltimore Oriole would move north to the point where there wouldn't be any Orioles in Baltimore. She explained that some bird species have a range that is defined by their food, others have a range that is defined by climate, making what will happen as climate changes an interesting subject to study.
Dr. Root did a study of something like 1700 plant and animal species to determine how species might change with global warming. There were four different types of changes: 1) Changes in range location; 2) Changes in abundance patterns; 3) Changes in timing of events; 4) Miscellaneous other changes. She found that 1479 of them had changed some trait, like migration patterns in the direction expected with global warming.
She gave an example of changes in species ranges that was a study she had done on the upper peninsula of Michigan. Some species had expanded their ranges so they were now residents rather than migrants. Some birds were migrating earlier, some had not changed their migration behavior, and one species had changed its migration to begin at a later date. (That species has declined in numbers dramatically.) She speculated that the species who hadn't changed their migration patterns were driven by a day length clock, whereas the others were driven by temperature considerations. Of the species who had changed their behavior, the avg. was to migrate about five days earlier per decade since the '70s.
Dr. Root had some wonderful anecdotes to go with her presentation. The release of her study had happened to coincide with a very slow news day, so it had gotten front page treatment in the New York Times. Tom Brokow had seen this, and decided to do a segment on it on the NBC Nightly News. He had introduced the segment on the air by saying "President Bush may not believe in Climate Change, but a lot of birds do."
For more info please visit: http://terryroot.stanford.edu/